Splitting Heirs is a minor royalty King Ralph, a breezy but lightweight comedy toplining Rick Moranis as a phony Yank heir to a Brit dukedom.
Moranis plays a motormouth Yank who becomes the 15th Duke of Bournemouth and head of the family bank when his father suddenly drowns. Unbeknownst to him, the real heir to the fortune is bank underling Eric Idle, who’s become his best pal.
Source of the confusion is Idle’s mom (Barbara Hershey) who left him in a restaurant during the Swinging Sixties and claimed the wrong baby at the police station. When Idle stumbles across the truth he tries every means to deep-six Moranis and claim his rightful fortune, in between fighting off the foxy Hershey who doesn’t realise he’s her son.
Even though it’s short of true belly-laughs, the dumb-sounding storyline plays better than it reads, thanks to brisk pacing, all-out playing by the main leads, and some okay sight gags once the plot cranks up into revenge mode.